Related Stories

Australia could dispose of a stockpile of toxic waste sitting in the middle of its biggest city without incinerating or exporting it, according to supporters of a technology said to provide a cleaner solution.

Supporters say the technnology can dispose of 16,000 tonnes of hexachlorobenzene (HCB) waste stored at the Sydney site of chemical company Orica.

If adopted, the technology could break a legal stalemate stopping the disposal of 8000 tonnes of concentrated HCB waste and 8000 tonnes of contaminated drums and rubble that Orica says are stockpiled at its Botany site.

But Orica is not convinced the technology can safely dispose of the HCBs, which are by-products of solvent manufacture, are a persistent organic pollutant (POP) and a suspected human carcinogen.

It says it has already assessed an earlier version of the technology, and wasn't impressed with its levels of emissions and contaminants.

Nevertheless, the company will later this month hear a presentation on an updated version of the technology, which has been backed by some environmentalists and engineers.

Perth-based engineer Trevor Bridle, who will be meeting with Orica later this month, is proposing a Canadian-developed technology called gas phase chemical reduction (GPCR).

He says while it's more expensive than incineration, it's a lot cleaner.

Closed-loop system

Bridle, who is a consultant for the company that owns the GPCR technology, says it involves converting the waste into a gas and combining it with hydrogen at high temperatures.

The resultant methane and excess hydrogen are fed back into the system to keep it going, he says.

"What comes out of it essentially all goes back into it," says Bridle.

He says other end-products, including carbon dioxide, water, ash, metal and sand are all tested for purity before recycling or landfill disposal.

"The real thing that the public is attracted to is that it is a closed-loop system," says Bridle.

He says an earlier version of the technology was used commercially at a Western Australian plant for six years in the 1990s to dispose of other POPs.

And he says trials with Orica's HCBs at this Kwinana plant showed the technology "could destroy 99.9999%" of the chemicals, meeting de facto international standards for POP disposal.

"We've seen it in practice," she says. "We have faith in the technology."

Murky history

While Orica has agreed to meet with Bridle, the company says its experience with GPCR hasn't been positive.

Contrary to Bridle's claim, an Orica spokesman says the Kwinana trials were not successful and there were safety concerns.

"There were unacceptably high emissions in the gas cleaning system and there was a significant amount of contaminants generated," he says.

"There is a significant safety concern with the use of hydrogen at high temperatures, which has an inherent fire and explosion risk."

But Bridle, who was involved in setting the Kwinana plant up, insists an independent assessment of the HCB trials there found it worked.

He also says GPCR has a 10 year track record of safe use at plants around the world and was given the thumbs up in a recent United Nations Industrial Development Organization report Non-combustion Technologies for POPs Destruction: Review and Evaluation on non-incineration waste disposal.

Bridle also says that since Kwinana, the technology has been updated and is now simpler, more operator friendly, more reliable and cheaper.

Legal dispute

Orica's attempts to dispose of the HCB waste are complicated by regulatory and legal issues.

In 2006 the company lodged an application with the Australian government to export the waste to incinerators in Germany on the grounds that the waste could not be dealt with in Australia.

But last year German authorities rejected Australia's claim it could not deal with the waste itself and Orica is now taking legal action.

In issuing support for the export of the HCBs to Germany last year, then environment minister Malcolm Turnbull said an "extensive analysis of Australia's waste disposal capabilities" found no capacity to destroy the HCBs.

The deliberations of his department's Hazardous Waste Technical Group on the issue are not publicly available.

But it is understood that the group's experts ruled out GPCR because there was no established commercial facility using the technology at that stage; the Kwinana plant closed in 2000.

It is also understood that the experts considered negative reports about GPCR, including those from Orica, but obtained no information directly from the promoters of GPCR themselves.

Moving forward

Bridle says he has been trying to meet with the technical group experts since August last year without success.

Lloyd-Smith claims says the technology is being downplayed because it's the hard option.

"We understand all the hard and dirty work of siting and establishing waste disposal facilities," she says.

"But it's totally unacceptable for a developed country like Australia to send hazardous waste off to let another community deal with it."

Lloyd-Smith says the Australian government should set up a full independent assessment of the GPCR technology.

The current federal environment minister Peter Garrett, whose electorate includes the Orica site, was unavailable for comment on whether he would reverse support for export should GPCR be found to be a solution for the waste.